Lamp capsule pinch seal and method of making such a seal

摘要

A pinch seal (7) for a low wattage ceramic metal halide lamp 1 which comprises a capsule (3) containing the operating parts of the lamp 1 and a pinch seal (7) closing the capsule at one end and containing the feed wires (9) for the lamp 1 in which the cross sectional shape (43) of the pinch (7) is determined by dimensional analysis of the capsule cross section prior to carrying out the pinch operation so as to give minimum of lateral flow of the quartz material. The invention also includes a method of making such a seal.